Metasurfaces based on integrated ferroelectric devices for phase control with enhanced optical transparency

A metasurface, comprising:

• a substrate;
• respective unit cells above the substrate, the respective unit cells comprising respective resonators having respective variable phases, the respective resonators comprising respective metal ring sets and respective voltage-controllable ferroelectric material varactor sets;
• and
• a mesh ground plane beneath the substrate, the mesh ground plane comprising openings that are optically transparent or substantially optically transparent,
• wherein the metasurface is a substantially optically transparent metasurface based on the substrate being transparent or substantially optically transparent, the mesh ground plane being transparent or substantially optically transparent, and dimensions of the respective resonators.

A unit cell, comprising:

• a resonating element, the resonating element comprising a ring resonator comprising at least two metallic parts divided by, and coupled to, at least one ferroelectric-based varactor set having variable permittivity;
• an optically transparent, or substantially optically transparent, substrate beneath the resonating element;
• and
• a metal mesh structure corresponding to a ground plane beneath the substrate, the metal mesh structure comprising optically transparent openings,
• wherein, in response to an electromagnetic wave impinging on the unit cell at a frequency that resonates the resonating element, the unit cell redirects an instance of the electromagnetic wave based on a reflection response determined by the variable permittivity of the at least one ferroelectric-based varactor set.